A callback function returning the HTML content or jQuery object to wrap around all the matched elements. Within the function, this refers to the first element in the set. Prior to jQuery 3.0, the callback was incorrectly called for every element in the set and received the index position of the element in the set as an argument.

The .wrapAll() function can take any string or object that could be passed to the $() function to specify a DOM structure. This structure may be nested several levels deep, but should contain only one inmost element. The structure will be wrapped around all of the elements in the set of matched elements, as a single group.

Demo:

Wraps a newly created tree of objects around the spans. Notice anything in between the spans gets left out like the <strong> (red text) in this example. Even the white space between spans is left out. Click View Source to see the original html.